Though the Torah prescribed capital punishment for certain crimes, the rabbis moderated its use.

The Bible prescribes the death penalty for a large number of offences including religious offences such as idol worship and the profaning of the Sabbath.
But the question of capital punishment in actual practice in ancient Jewish society is extremely complicated.

Talmudic Restrictions

According to the Mishnah (Sanhedrin 1:4) the death penalty could only be inflicted, after trial, by a Sanhedrin composed of twenty-three judges and there were four types of death penalty (Sanhedrin 7:1): stoning, burning, slaying (by the sword), and strangling. A bare reading of these and the other accounts in the tractate would seem to suggest a vast proliferation of the death penalty. Yet, throughout the Talmudic literature, this whole subject is viewed with unease, so much so that according to the rules stated in that literature the death penalty could hardly ever have been imposed.

For instance, it is ruled that two witnesses are required to testify not only that they witnessed the act for which the criminal has been charged but that they had warned him beforehand that if he carried out the act he would be executed, and he had to accept the warning, stating his willingness to commit the act despite his awareness of its consequences. The criminal's own confession is not accepted as evidence. Moreover, circumstantial evidence is not admitted.

From Practice to Theory

It has to be appreciated, however, that practically all this material comes from a time when the right to impose the death penalty had been taken away from the Jewish courts by the Roman authorities. According to one report in the Talmud (Sanhedrin 41a) the power of the Jewish courts to the death penalty ceased around the year 30 BCE; according to another report (Sanhedrin 52b) it could only have been imposed while the Temple stood and must have come to an end not later than 70 CE when the Temple was destroyed.

This means that, although earlier traditions may be present in the Mishnaic formulations, the whole topic, including the restrictions, is treated in the Mishnah and the Talmud in a purely theoretical way. It is hard to believe that when the courts did impose the death penalty they could only do so when the conditions above obtained. Who would commit a murder in the presence of two witnesses when these had solemnly warned him that if he persisted they would testify against him to have him executed for his crime?

That the Mishnaic material is purely on the theoretical level can be seen from the oft-quoted statement (Mishnah Makkot 1:10): "A Sanhedrin that puts a man to death once in seven years is called destructive. Rabbi Eliezer ben Azariah says: even once in seventy years. Rabbi Akiba and Rabbi Tarfon say: had we been in the Sanhedrin none would ever have been put to death. Rabban Simeon ben Gamaliel says: they would have multiplied shedders of blood in Israel."